1. Field of the Invention
This application is directed to lubricant compositions comprising oils of lubricant viscosity or greases prepared therefrom containing a minor amount, sufficient to improve the load-carrying properties thereof, of organophosphorus derivatives of alkyl or aryl hydroxycarboxylic acids, and to said organophosphorus derivatives.
2. Description of the Prior Art
The use of phosphorus compounds, per se, as load-carrying or EP agents in lubricant compositions is well known. The use of organic phosphorus compounds in combination with, for example, hindered phenols to produce load-carrying additives for lubricants in known from U.S. Pat. Nos. 3,115,465; and 3,986,967 discloses organophosphorus derivatives of benzotriazole with the ability to support higher load factors. So far as is known, however, no art exists which suggests the herein disclosed reaction products of certain hydroxycarboxylic acids and organophosphorus compounds, or use thereof as load-carrying agents.